| Company Name | Company Location | Company Type | Most Recent Production | |
|---|---|---|---|---|
| 1 | Umc Petroleum Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 2 | Underground Energy Inc. | Oil & Gas Operator | Aug 2025 | |
| 3 | Union Development Company Inc | Oil & Gas Operator | Dec 1992 | |
| 4 | Union Oil Co Of California | Midland, TX 79706 | Oil & Gas Operator | Jan 2022 |
| 5 | Union Pacific Resources Co. | Fort Worth, TX 76101 | Oil & Gas Operator | Jan 2001 |
| 6 | United Energy, Inc. | Wichita, KS 67230 | Oil & Gas Operator | Dec 2002 |